[io grant] Amend IO::Path.resolve: :completely
[io grant] Amend IO::Path.resolve: :completely

To include the bit that the last path fragment does not have to exist.

Rakudo correction: https://github.com/rakudo/rakudo/commit/51e462925a
Tests: https://github.com/perl6/roast/commit/a716962791

antquinonez/doc,perl6/doc,antquinonez/doc,perl6/doc,stmuk/doc,jonathanstowe/doc,gfldex/doc,gfldex/doc,antquinonez/doc,stmuk/doc,tbrowder/doc,jonathanstowe/doc,jonathanstowe/doc,antquinonez/doc,jonathanstowe/doc,MasterDuke17/doc,perl6/doc,dmaestro/doc,dmaestro/doc,MasterDuke17/doc,stmuk/doc,tbrowder/doc,antquinonez/doc,stmuk/doc,gfldex/doc,dmaestro/doc,dmaestro/doc,MasterDuke17/doc,gfldex/doc,tbrowder/doc,dmaestro/doc,gfldex/doc,tbrowder/doc,jonathanstowe/doc,perl6/doc,MasterDuke17/doc,perl6/doc,stmuk/doc